Apparatus for golf training

ABSTRACT

There is provided an apparatus for training a golf which includes: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a shot state checking unit connected to each of the shot sensing units, for checking a down blow state or a duff state by a sensed signal outputted from the shot sensing units and outputting a voice.

[0001] This application claims priority of pending Korean Patent Application No. 2002-83851 filed on Dec. 26, 2002.

FIELD OF THE INVENTION

[0002] The present invention relation to an apparatus for golf training, and more particularly, to an apparatus for golf training, in which a shot sensing unit is installed below portions before and behind positions where a golf ball is placed on a golf training mat to after a golf trainee hits the golf ball, confirm the down blow and selectively recognize by himself (or herself) whether or not there exists a head up, thereby enabling a golf training.

DESCRIPTION OF THE RELATED ART

[0003] To play the golf well, it is necessary to utilize characteristic of the golf club well and at the same time become skilled in a correct posture. In particular, in case of iron, the preciseness in the advancing direction can be expected by the golf club blowing the golf ball down.

[0004] Down blow indicates to strike the golf ball before the center of the club head reaches the lowest point of swing from the top of swing. After striking the golf ball, the club head is in contact with a mat surface at a point right beyond the position where the golf ball was put.

[0005] However, in case of most of initiators, there frequently occurs duff that a bottom portion of the club head is directly in contact with a surface right below a position where the golf ball is put or behind a position where the golf ball is put. Also, the initiators cannot perceive whether or not they committed the down blow.

[0006] Also, after shots are carried out, head up phenomenon (face is early directed toward a target prior to striking the golf ball) may occur. Hence, the initiators have to correct the down blow and head up postures in the course of training. Since this posture correction should be performed by a skilled trainer, training by himself (or herself) fails to correctly recognize the postures.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide an apparatus for training a golf, in which a golf initiator himself or herself can confirm a success of a down blow and selectively a head up.

[0008] Another object of the present invention is to provide an apparatus for training a golf, in which shot sensing switches are installed in a down blow position and a duff position on a mat formed in a base frame with a predetermined size adaptable for golf training, thereby making a golf trainee recognize a success of shot by a sound signal.

[0009] Further another object of the present invention is to provide an apparatus for training a golf, in which a lamp is installed near a position where a golf ball is put and a golf trainee is guided to look at a lamp for a predetermined time, thereby making it possible to correct a posture in order for a prevention of a head up.

[0010] According to one aspect of the present invention, an apparatus for training a golf comprises: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a shot state checking unit connected to each of the shot sensing units, for checking a down blow state or a duff state by a sensed signal outputted from the shot sensing units and outputting a voice.

[0011] Preferably, the shot state checking unit includes a pair of lamps emitting light according to the down blow state or the duff state, and the apparatus further comprises a lamp lighting control unit for controlling a lighting time of the lamp.

[0012] In an embodiment of the present invention, the lamp lighting control unit includes: a relay receiving the sensed signal from the shot sensing unit; and a relay switch controlled by the relay to apply a voltage to the lamp according to the sensed signal for a predetermined time.

[0013] In another embodiment, the lamp lighting control unit includes: a timer having a ground terminal, a power terminal, a trigger terminal, an output terminal and a discharge terminal; a switch having one end connected to the trigger terminal and the other terminal connected to the shot sensing unit; a resistor and a capacitor connected in parallel to the discharge terminal, wherein a resistance of the resistor and a capacitance of the capacitor are adjusted to control a time to output a voltage driving the lamp through the output terminal according to a control signal inputted from the shot sensing unit through the switch.

[0014] In further another embodiment, the lamp lighting control unit includes a microcomputer, the lamp being lighted for a predetermined time till before an interrupt is generated in the microcomputer with respect to an input signal generated from the shot sensing unit by using an internal clock of the microcomputer.

[0015] According to another aspect of the present invention, an apparatus for training a golf comprises: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a main switch connected to an output terminal of the power supply unit; a lamp selecting switch and a sound selecting switch each being switched by a golf trainee, each end portion of which is connected in parallel to the main switch; and a shot state checking unit having a down blow lamp/a duff lamp and a sound generating unit, the down blow lamp/the duff lamp being connected to the lamp selecting switch and lighted for a predetermined time according to a signal outputted from the shot sensing unit, the sound generating unit being connected to the sound selecting switch and outputting a sound according to the signal outputted from the shot sensing unit.

[0016] According to further another aspect of the present invention, an apparatus for training a golf comprises: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a shot state checking unit connected to each of the shot sensing units, for checking a down blow state or a duff state by a sensed signal outputted from the shot sensing units and outputting a voice, wherein the shot sensing unit includes: a switch plate fixed in a reception space formed on the base and spaced apart from the mat; a lower contact plate fixed to a bottom surface of the switch plate; and an upper contact plate installed in the switch plate and facing the lower contact plate, the upper contact plate being connected elastically movable up and down with respect to the switch plate and being electrically connected to the lower contact plate by a blow of the club head.

BRIEF DESCRIPTION OF DRAWINGS

[0017] The above objects and other advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:

[0018]FIG. 1 illustrates a circuit applied to an apparatus for training a golf according to an embodiment of the present invention;

[0019]FIG. 1A illustrates a circuit for controlling an on-time of the lamp of FIG. 1 according to an embodiment of the present invention;

[0020]FIG. 2 is a perspective view of an apparatus for training a golf according to the present invention;

[0021]FIG. 3 is an exploded perspective view showing a mechanical construction of a shot sensing unit according to the present invention;

[0022]FIG. 4 is a plan view of the shot sensing unit according to the present invention;

[0023]FIG. 5 is a sectional view showing a switch plate fixed to a base according to the present invention;

[0024]FIG. 6 is a sectional view showing a movement state of a club head according to the present invention;

[0025]FIG. 7 is a sectional view showing an off state of the sensing switch according to the present invention; and

[0026]FIG. 8 is a sectional view showing an on state of the sensing switch according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0027] Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0028]FIG. 1 illustrates a circuit applied to an apparatus for training a golf according to the present invention, and FIG. 2 is a perspective view of the apparatus for training the golf according to the present invention.

[0029] Referring to FIG. 1, the circuit applied to the apparatus for training the golf according to the present invention includes a main switch 10, a selecting switch 11 having a lamp selecting switch 11 a and a sound selecting switch 11 b, a shot sensor 12, a sound generator 13, first and second relays 14 and 14 a, a down blow lamp 15, a duff lamp 15 a, and first and second relay switches 16 and 16 a operated by the first and second relays 14 and 14 a.

[0030] The main switch 10 is supplied with a power supply voltage Vcc and has an output terminal branched into each input terminal of the lamp and sound selecting switches 11 a and 11 b of the selecting switch 11.

[0031] The lamp and sound selecting switches 11 a and 11 b selectively operate the down blow and duff lamps 15 and 15 a and the sound generator 13, respectively. The lamp selecting switch 11 a is connected to the first and second relays 14 and 14 a and the down blow and duff lamps 15 and 15 a, and the sound selecting switch 11 b is connected to the sound generator 13.

[0032] The shot sensor 12 includes a down blow sensing switch 12 a and a duff sensing switch 12 b.

[0033] The down blow sensing switch 12 a has an output terminal OUT1 connected to both an enable terminal EN1 of the sound generator 13 and the first relay 14. The duff sensing switch 12 b has an output terminal OUT2 connected to both an enable terminal EN2 of the sound generator 13 and the second relay 14 a.

[0034] As shown in FIGS. 2 to 4, a mechanical construction of the down blow sensing switch 12 a and the duff sensing switch 12 b is provided with switches formed by respective contact points between a base 100 and an artificial turf mat 120. As shown in FIG. 6, the down blow sensing switch 12 a is installed before a position of a golf ball 300 placed on the artificial turf mat 120, and the duff sensing switch 12 b is installed behind the golf ball 300.

[0035] In other words, the down blow sensing switch 12 a is formed in a position where the down blow is achieved, and the duff sensing switch 12 b is formed in a position where the down blow fails.

[0036] According to an operation of the shot sensor 12, when a club head strikes the golf ball 300, the down blow sensing switch 12 a is turned on to output a control signal informing a success of the down blow through the output terminal OUT1 of the down blow sensing switch 12 a. If the duff sensing switch 12 b is turned on, a control signal informing a failure of the down blow is outputted through the output terminal OUT2 of the duff sensing switch 12 b.

[0037] The sound generator 13 is connected to the shot sensor 12 and outputs respective set sounds according to the control signal informing the success or the failure of the down blow.

[0038] In case the down blow succeeds, the first relay 14 is excited in response to the signal outputted from the output terminal OUT1 of the shot sensor 12 to thereby turn on the first relay switch 16 to light the down blow lamp 15. In case the down blow fails, the second relay 14 a is excited in response to the signal outputted from the output terminal OUT2 of the shot sensor 12 to turn on the second relay switch to light the duff lamp 15 a.

[0039] Accordingly, if the down blow succeeds, the down blow lamp 15 is lighted, and if the down blow fails, the duff lamp 15 a is lighted.

[0040] A golf trainee turns on the main switch 10 and selects one or both of the lamp selecting switch 11 a and the sound selecting switch 11 b according to whether to train the prevention of the head up using the lamp, whether to check the down blow using a sound, or whether to train the prevention of the head up while checking the down blow.

[0041] Therefore, if the lamp selecting switch is set to the on state, the first and second relays 14 and 14 a becomes a ready state. Then, the down blow lamp 15 and the duff lamp 15 a are selectively lighted according to the control signals outputted from the shot sensor 12. If the sound selecting switch 11 b is set to the on state, the sound generator 13 becomes a ready state.

[0042] The down blow and duff lamps 15 and 15 a and the sound generator 13 are driven simultaneously in order to check the down blow and train the prevention of the head up at the same time.

[0043] As shown in FIG. 6, if the golf trainee swings the club in a state that both the lamp and sound selecting switches 11 a and 11 b are set to the on state, the club head 200 contacts with the mat 120. At this time, if the golf trainee swings normally, the club head 200 contacts with the mat 120 at a slight front in a progress direction of the golf ball 300, such that the down blow sensing switch 12 a is operated. If the down blow sensing switch 12 a is operated, the down blow lamp 15 is lighted by the sound generator 13 and the first relay 14 since the output terminal OUT1 of the down blow sensing switch 12 a is connected to the enable terminal EN1 of the sound generator 13 and the first relay 14. At the same time, the sound generator 13 outputs a sound notifying that the down blow succeeds, for example, a voice like “good shot”. At this time, it is preferable that the down blow lamp 15 is lighted for 2 to 3 seconds. The control signal outputted from the output terminal OUT1 of the shot sensor 12 allows the first relay 14 to drive the first relay switch 16 for 2 to 3 seconds and then put out the down blow lamp 15.

[0044] In other words, in case the golf trainee performs the shot normally and succeeds in the down blow, the golf trainee can check the down blow by the sound outputted from the sound generator 13. At the same time, the head up can be prevented by checking the down blow lamp 15 that is lighted for 2 to 3 seconds.

[0045] It is preferable to make a difference between the down blow lamp 15 and the duff lamp 15 a. For example, a green lamp is used to notify the success of the down blow.

[0046] If the golf trainee does not perform the normal swing so that the club head 200 contacts with the mat 120 before it contacts with the golf ball 300, the duff sensing switch 12 b is operated. If the duff sensing switch 12 b is operated, the duff lamp 15 a is lighted by the sound generator 13 and the second relay 14 a since the output terminal OUT2 of the duff sensing switch 12 b is connected to the enable terminal EN2 of the sound generator 13 and the second relay 14. At the same time, the sound generator 13 outputs a sound notifying that the down blow fails, for example, a voice like “no good”. A red lamp can be applied to the duff lamp 15 a in order to easily make a difference between the duff lamp 15 a and the down blow lamp 15 and notify the failure of the down blow.

[0047] It is preferable to cause the second relay 14 a to drive the second relay switch 16 a for a predetermined time in order to light the duff lamp for 2 to 3 seconds. Even though the down blow is not achieved, the training for preventing the head up can be achieved continuously.

[0048] In this manner, the golf trainee can train with a correct posture by preventing the head up while looking at the down blow lamp 15 and the duff lamp 15 a for a predetermined time. Therefore, it is preferable to place the down blow lamp 15 and the duff lamp 15 a near to a position where the golf ball is placed.

[0049] The golf trainee can recognize his/her shot state and train the prevention of the head up by selectively checking one or both of the lighting of the down blow and duff lamps 15 and 15 a and the voice outputted from the sound generator 13.

[0050] Parts that those skilled in the art can modify easily are included in the above embodiment. A description about the parts will be made below.

[0051]FIG. 1A shows a circuit for implementing the operations of the first and second relays 14 and 14 a, the first and second lamps 15 and 15 a and the switches 16 and 16 a with a timer 130.

[0052] Referring to FIG. 1A, the shot sensor 12 outputting the control signal through the output terminal OUT1 corresponds to a switch 131. The first relay 4 and the first relay switch 16 correspond to the timer 130 and resistors R1, R2 and R3 and capacitors C1 and C2, which are connected to the timer 130. The down blow lamp 15 corresponds to a diode 134.

[0053] If the signal generated from the output terminal OUT1 of the shot sensor 12 by the golf trainee's shot is inputted through the operation of the switch 131, 0 V is applied to a TG terminal of the timer 130 and the timer is operated. At this time, a DIS terminal is opened at the same time when an OUT terminal is se to a high level. Accordingly, the capacitor 133 that is always discharged through the DIS terminal begins to be charged through the resistor 132.

[0054] If the voltage becomes two third of the power supply voltage, the output signal is set to a low level and the charges of the capacitor 133 are discharged through the DIS terminal.

[0055] A time when the output signal is maintaining a high level is determined by the time when the capacitor 133 is being charged through the resistor 132.

[0056] The time can be calculated by multiplying a capacitance of the capacitor 133 by a resistance of the resistor 132. For example, if the capacitance is 2.F(0.000003F) and the resistance is 1 M. (1,000,000.), the time is 2 seconds.

[0057] In order to obtain a more accurate time, a variable resistor can be used as the resistor 132. The accurate operation time matched with the situation of the golf trainee can be set by adjusting the variable resistor while inputting the operation of the switch 131 and measuring the operation time of the diode 134.

[0058] The diode 134 connected to the OUT terminal of the timer 130 can be lighted for 2 seconds by the operation of the switch 131. However, instead of the analog relay circuit using the timer, it is preferable to configure the relay circuit using a microcomputer such as PIC16C84 or PIC16F84, which is a semiconductor chip having CPU function. In this case, an error can be minimized and the operation time can be set through the command set to the microcomputer.

[0059] Specifically, PIC16C84 has one embedded 8-bit timer/counter. The function as the timer is to generate an interrupt after a predetermined time by using an internal clock. At this time, an accurate time is measured through an operation of the counter according to an input signal of the switch 131, and the interrupt is generated just after a predetermined time to thereby stop the operation.

[0060] It is important to consider the mechanical conditions of the down blow sensing switch 12 a and the duff sensing switch 12 b. This is because the club head moving at a high speed heavily blows the surface of the artificial turf mat 120 when the golf trainee tries the shot to thereby cause a damage of the sensing switch.

[0061] A mechanical construction of the shot sensor 12 capable of securing semi-permanent lifetime will be described with reference to FIGS. 3 to 5.

[0062] A switch plate 150 is inserted into a reception space defined on a predetermined position of a base 100 and fixed to the base 100 by a base fixing bracket 171 protruded sideward and a screw 178. A stepped portion 101 is formed at the center from the reception space to the surface of the base 100. The mat 120 is supported by the stepped portion to thereby form a space between the back of the mat 120 and the switch plate 150.

[0063] The switch plate 150 includes a pair of sidewalls 152 facing each other and a bottom surface 151 connecting lower portions of the sidewalls. A lower contact plate 170 is fixedly installed on both lower surfaces of the switch plate 150. Preferably, the lower contact plate 170 can be fixed to the switch plate by means of set screw 176 or spot welding.

[0064] The base fixing brackets 171 is protrudedly formed at predetermined intervals along upper edges of the sidewalls 152, and screw holes 173 are formed in the base fixing bracket 171. In addition, contact plate fixing brackets 177 are formed inwardly from the upper edges of the sidewalls 152 centering on a lower contact plate 170. An insertion hole 175 is formed on the fixing bracket 177 and a screw groove 174 is formed on a lower surface 151 of the switch plate 150 on an extended line of the insertion hole 175.

[0065] A reinforcement plate 163 with a predetermined thickness is formed at the center of the surface of the upper contact plate 160 in order to reinforce the strength with respect to the impact of the club head. An insertion hole 161 is perforated at a position corresponding to the insertion hole 175 of the switch fixing bracket 177 formed on the switch plate 150. As shown in FIG. 5, a plurality of switch terminals 164 are protrudedly formed on the bottom portion at predetermined intervals.

[0066] The upper contact plate 160 is inserted from the end portion of the switch plate 150 and coupled to the switch plate 150 from the lower portion of the insertion hole 175 of the switch fixing bracket 177. In more detail, the insertion hole 161 of the upper contact plate 160 are disposed to match with the insertion hole 175 of the switch fixing bracket 177. Then, a compression coil spring 162 is interposed into the back of the upper contact plate 160. A guide screw is inserted from the upper portion of the insertion hole 175 and fixed to the lower surface 151 through the insertion hole 175, the insertion hole 161, the compression coil spring 162, the screw groove 174 in sequence.

[0067] Accordingly, the upper contact plate 160 is always in a floating state due to the compression force of the compression coil spring 162. If a force is applied from the upper portion, the upper contact plate 160 rises or falls by the guidance of the guide screw 176.

[0068] The upper contact plate 160 installed as above and the lower contact plate 170 fixed to the lower surface are paired to configure the down blow sensing switch 12 a and the duff sensing switch 12 b.

[0069] The down blow sensing switch 12 a and the duff sensing switch 12 b have the same structure and are formed symmetrically on both sides of the switch plate 150. the down blow sensing switch 12 a is formed at a position where the down blow happens in the switch plate 150, that is, a position before the golf ball. The duff sensing switch 12 b is formed at a position where no down blow happens, that is, a position behind the golf ball.

[0070] In FIG. 3, there is shown the down blow sensing switch 12 a separated from the switch plate 150 and the duff sensing switch 12 b fixed thereto.

[0071] If a force is applied from the upper portion, the down blow sensing switch 12 a and the duff sensing switch 12 b acts as a push switch. In other words, as shown in FIG. 6, on the rotation orbit of the swing motion of the club head 200 at the upper portion of the mat 120, the down blow sensing switch 12 a is installed before a position P where the golf ball 300 is placed on the mat 120, and the duff sensing switch 12 b is installed behind the position P where the golf ball 300 is placed. In the swing, the contact of the down blow sensing switch 12 a or the duff sensing switch 12 b is formed due to a pressing force generated when the club head 200 glances the mat 120, so that the shot, thereby sensing the shot state.

[0072] The mat 120 operating the down blow sensing switch 12 a or the duff sensing switch 12 b is recovered to the original state due to its own elasticity. The down blow sensing switch 12 a and the duff sensing switch 12 b become short while the upper contact plate 160 rises due to the elasticity of the respective compression coil spring 162.

[0073]FIGS. 7 and 8 illustrate the operation state of the switch of the shot sensor 12. In detail, FIGS. 7 and 8 illustrate an off state and an on state of the switch of the sensor 12, respectively.

[0074] In other words, FIG. 7 illustrates the off state of the switch when the upper contact plate 160 and the lower contact plate 170 are spaced apart from each other by the compression coil spring 162. FIG. 8 illustrates the on state, when the club head 200 contacts with the mat 120 in the golf trainee's swing, the reinforcement plate 163 is pressed while pressing the contact portion of the mat 120, and the upper contact plate 160 and the lower contact plate 170 contact with each other. The on state occurs due to the instantaneous contact according to the golf trainee's swing. The mat 120 is recovered to the original state due to its own elasticity, and the upper contact plate 160 rises due to the compression coil spring 162.

[0075] The present invention can prevent the trainee from the head up by guiding the trainee to look at the lighting and light-out of the lamp according to the swing states without the help of the trainer and can check whether the down blow succeeds by the sound. Therefore, the trainee can train while correcting the posture autonomously.

[0076] In such an autonomous training, the lighting of the lamp and the generation of the sound are selectively possible by the selective manipulation of the lamp selecting switch and the sound selecting switch. In one apparatus for training the golf, the head up correction and the down blow correction can be performed selectively or simultaneously.

[0077] Further, durability of the switch is improved through a structural improvement of the shot sensor formed on the contact portion between the club head and the mat, thereby securing the semi-permanent lifetime.

[0078] While the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims. 

What is claimed is:
 1. An apparatus for training a golf, comprising: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a shot state checking unit connected to each of the shot sensing units, for checking a down blow state or a duff state by a sensed signal outputted from the shot sensing units and outputting a voice.
 2. The apparatus of claim 1, wherein the shot state checking unit includes a pair of lamps emitting light according to the down blow state or the duff state, and the apparatus further comprises a lamp lighting control unit for controlling a lighting time of the lamp.
 3. The apparatus of claim 2, wherein the lamp lighting control unit includes: a relay receiving the sensed signal from the shot sensing unit; and a relay switch controlled by the relay to apply a voltage to the lamp according to the sensed signal for a predetermined time.
 4. The apparatus of claim 2, wherein the lamp lighting control unit includes: a timer having a ground terminal, a power terminal, a trigger terminal, an output terminal and a discharge terminal; a switch having one end connected to the trigger terminal and the other terminal connected to the shot sensing unit; a resistor and a capacitor connected in parallel to the discharge terminal, wherein a resistance of the resistor and a capacitance of the capacitor are adjusted to control a time to output a voltage driving the lamp through the output terminal according to a control signal inputted from the shot sensing unit through the switch.
 5. The apparatus of claim 2, wherein the lamp lighting control unit includes a microcomputer, the lamp being lighted for a predetermined time till before an interrupt is generated in the microcomputer with respect to an input signal generated from the shot sensing unit by using an internal clock of the microcomputer.
 6. An apparatus for training a golf, comprising: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a main switch connected to an output terminal of the power supply unit; a lamp selecting switch and a sound selecting switch each being switched by a golf trainee, each end portion of which is connected in parallel to the main switch; and a shot state checking unit having a down blow lamp/a duff lamp and a sound generating unit, the down blow lamp/the duff lamp being connected to the lamp selecting switch and lighted for a predetermined time according to a signal outputted from the shot sensing unit, the sound generating unit being connected to the sound selecting switch and outputting a sound according to the signal outputted from the shot sensing unit.
 7. An apparatus for training a golf, comprising: a base in which a power supply unit is embedded; a mat formed attachably and detachably to the base; a pair of shot sensing units installed between the base and the mat in a down blow position and a duff position centering on a golf ball, for sensing a blow of a club head; and a shot state checking unit connected to each of the shot sensing units, for checking a down blow state or a duff state by a sensed signal outputted from the shot sensing units and outputting a voice, wherein the shot sensing unit includes: a switch plate fixed in a reception space formed on the base and spaced apart from the mat; a lower contact plate fixed to a bottom surface of the switch plate; and an upper contact plate installed in the switch plate and facing the lower contact plate, the upper contact plate being connected elastically movable up and down with respect to the switch plate and being electrically connected to the lower contact plate by a blow of the club head. 